State Key Laboratory on Marine Resource Utilization in South China Sea, Hainan Provincial Key Laboratory of Research on Utilization of Si-Zr-Ti Resources, College of Materials Science and Chemical Engineering, Hainan University, 58 Renmin Road, Haikou 570228, China.
Phys Chem Chem Phys. 2018 Nov 14;20(44):28176-28184. doi: 10.1039/c8cp05561k.
LiBC is a layered boron carbide material that was first studied as a superconducting material. Theoretical study showed that LiBC is a promising cathode material in Li-ion batteries, while our early computational and experimental studies demonstrated the feasibility of LiBC as a high-capacity anode material for Li-ion batteries. In this work, LiBC has been synthesized by a solid-state method using different carbon precursors of acetylene black and graphite, marked a-LiBC and g-LiBC, respectively, and their electrochemical properties and corresponding structure evolutions have been investigated in Li-ion batteries. As a result, a-LiBC delivers a higher specific capacity than g-LiBC, 500 mA h g-1vs. 200 mA h g-1, after 50 cycles at a rate of 0.1C. Actually, a significant structural evolution of a-LiBC was observed by in situ XRD during the charge/discharge processes, while a nearly constant structure was detected for g-LiBC. Meanwhile, in situ Raman results revealed the evolution of vibrational beating modes at different charge/discharge states. Therefore, the specific capacity of LiBC is closely related to its crystallinity, and LiBC with amorphous carbon precursors could be adopted as a promising anode material for Li-ion batteries.
LiBC 是一种层状碳化硼材料，最初被研究为超导材料。理论研究表明，LiBC 是锂离子电池中很有前途的阴极材料，而我们早期的计算和实验研究证明了 LiBC 作为锂离子电池高容量阳极材料的可行性。在这项工作中，LiBC 通过使用不同的碳前体乙炔黑和石墨的固态方法合成，分别标记为 a-LiBC 和 g-LiBC，并研究了它们在锂离子电池中的电化学性能及其相应的结构演变。结果表明，a-LiBC 在 0.1C 的速率下经过 50 次循环后的比容量高于 g-LiBC，为 500 mA h g-1vs. 200 mA h g-1。实际上，在充电/放电过程中通过原位 XRD 观察到 a-LiBC 的显著结构演变，而 g-LiBC 的结构几乎保持不变。同时，原位拉曼结果揭示了不同充放电状态下振动拍频模式的演变。因此，LiBC 的比容量与其结晶度密切相关，采用具有非晶态碳前体的 LiBC 作为锂离子电池的一种有前途的阳极材料。
